Note: A severe weather area depicted in the Day 4-8 period indicates a 30% or higher probability for severe thunderstorms within 25 miles of any point.

PREDICTABILITY TOO LOW is used to indicate severe storms may be possible based on some model scenarios. However, the location or occurrence of severe storms are in doubt due to: 1) large differences in the deterministic model solutions, 2) large spread in the ensemble guidance, and/or 3) minimal run-to-run continuity.

POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears highly unlikely during the entire period (e.g. less than a 30% probability for a regional severe storm area across the CONUS through the entire Day 4-8 period).

Forecast Discussion

ZCZC SPCSWOD48 ALL
ACUS48 KWNS 250900
SPC AC 250900
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0400 AM CDT SAT AUG 25 2012
VALID 281200Z - 021200Z
...DISCUSSION...
00Z ECMWF/GEFS/UKMET ARE IN GENERAL AGREEMENT REGARDING THE LIKELY
PERSISTENCE OF A RELATIVELY AMPLIFIED BELT OF WESTERLIES OVER CANADA
AND THE NORTHERN TIER OF THE CONUS FOR MUCH OF THE PERIOD...ALTHOUGH
MODEL VARIABILITY REGARDING LOWER AMPLITUDE FEATURES INCREASES BY
MID-WEEK /DAY 5/ AND BEYOND.
THE PRIMARY FOCUS FOR THE OUTLOOK PERIOD WILL RELATED TO THE
PROBABLE LANDFALL/INLAND MOVEMENT OF ISAAC ACROSS THE GULF COAST
REGION/SOUTHEAST STATES BASED ON THE LATEST NHC FORECAST
TRACK/INTENSITY. IN ASSOCIATION WITH THE PERIPHERAL OUTER
BANDS/EVENTUAL REMNANTS OF ISAAC...A TORNADO THREAT WILL LIKELY BE A
DISTINCT POSSIBILITY ACROSS PORTIONS OF FL/GA/AL ON DAY
4/TUESDAY...AND A SEVERE RISK AREA HAS BEEN INCLUDED FOR THIS
SCENARIO. TORNADO POTENTIAL MAY CONTINUE INTO DAYS 5-6
WEDNESDAY/THURSDAY ACROSS THE CENTRAL GULF COAST/SOUTHEAST
STATES...ALTHOUGH VARIABILITY/UNCERTAINTY INCREASES MARKEDLY BY THIS
TIME FRAME REGARDING THE DETAILS.
ELSEWHERE...AT LEAST SOME SEVERE POTENTIAL MAY EXIST MID INTO LATE
WEEK ACROSS PORTIONS OF THE NORTHERN PLAINS AND/OR UPPER MIDWEST.
HOWEVER...UNCERTAINTY EXISTS REGARDING THE FORECAST ADVANCEMENT OF A
LOWER AMPLITUDE TROUGH OVER SOUTHERN CANADA AND THE
NORTHWEST/NORTH-CENTRAL CONUS DURING THIS TIME FRAME.
..GUYER.. 08/25/2012
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